<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <link rel="stylesheet" href="style.css">
    <title>Index</title>
    <script src="main.js"></script>
</head>
<body>
<h1>你好HTTP</h1>
<div class="app">
    <button class="btn" id="add">Add</button>
    <span id="count" class="count"></span>
    <button class="btn" id="sub">Sub</button>
</div>
</body>
</html>